Driving Arrangement For Construction Machine

ABSTRACT

The present disclosure relates to a driving arrangement for a construction machine, such as an excavator, comprising a hydraulic pump for powering a working equipment and/or locomotion of the construction machine through a hydraulic circuit, an electric motor for driving the hydraulic pump, wherein power of the electric motor is transferable to the hydraulic pump via a connection means, a supporting device for mounting the driving arrangement to the construction machine, the supporting device supporting the hydraulic pump and the electric motor, and an adjustment mechanism for adjusting the positional relationship between the electric motor and the hydraulic pump to align both component with respect to each other.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to International Application No.PCT/CN2019/104136 filed on Sep. 3, 2019, the entire disclosure of whichis incorporated by reference.

TECHNICAL FIELD

The present invention relates to a driving arrangement for aconstruction machine, and to a construction machine comprising such adriving arrangement. The construction machine may be an excavator.

BACKGROUND

Electrical excavators are known, which comprise an electrical storagedevice for powering an electrical motor, the electrical motor driving ahydraulic pump via which hydraulic actuators of the excavator's boom maybe actuated. CN 10 496 337 5 A relates to an excavator comprising anelectric motor and a hydraulic pump.

SUMMARY OF THE INVENTION

The present invention relates to a driving arrangement for aconstruction machine. The construction machine may be an excavator orany other type of construction machine. The excavator may comprise anundercarriage and a superstructure, which is pivotably provided on theundercarriage. The undercarriage may comprise one or multiple tracks forlocomotion of the excavator, i.e. for moving the excavator forwards,backwards and/or sidewards. The construction machine, e.g. thesuperstructure of the excavator, may comprise a boom with multiple arms,which are movable with respect to each other via hydraulic actuators.The hydraulic actuators may be part of a hydraulic circuit of theconstruction machine.

The driving arrangement of the present invention comprises a hydraulicpump for powering a working equipment and/or locomotion of theconstruction machine through a hydraulic circuit. According to anembodiment, the hydraulic pump is suitable for powering theabove-described hydraulic circuit comprising the multiple hydraulicactuators for moving the multiple arms of the construction machine'sboom. Additionally or alternatively, the hydraulic pump may beconfigured to power a further hydraulic circuit via which means forlocomotion of the excavator, e.g. tracks, may be driven. Furthermore,the driving arrangement comprises an electric motor for driving thehydraulic pump via a connection means. The electric motor is configured,e.g. exhibits an output torque/power, suitable for driving the hydraulicpump. The electric motor may be a synchronous or asynchronous motor.According to an embodiment, the driving arrangement comprises only thisone electric motor for driving the hydraulic pump, implying that thehydraulic pump is not driven by any other power source, in particularnot by a combustion engine. The electric motor may be powered by anelectrical storage unit, which may comprise multiple battery packs,wherein each battery pack may comprise multiple battery cells. Each ofthe battery packs may be configured to provide a current of multiplehundreds of Ampere, e.g. at a rated voltage of approximately 100V. Inparticular, the construction machine, e.g. the excavator, may be a pureelectric excavator only comprising an electrical storage device as powersource, in particular not comprising a combustion engine.

In addition, the driving arrangement comprises a supporting devicesuitable to mount the driving arrangement to the construction machine.The supporting device may be made from multiple components, which may beconnected to each other via material bonding, e.g. welding, and/orbolts/screws or which may be integrally formed with each other. Thesupporting device may be made from steel. The supporting device supportsthe hydraulic pump and the electric motor. Specifically, the hydraulicpump and the electric motor are mounted to the supporting device.Furthermore, the driving arrangement comprises an adjustment mechanismfor adjusting the positional relationship between the electric motor andthe hydraulic pump to align both components with respect to each other.The adjustment mechanism may be provided by the supporting device and/orby a separate arrangement. The positional relationship may be adjustedby displacing the electric motor and the hydraulic pump with respect toeach other in a linear fashion and/or by rotating both components withrespect to each other.

The driving arrangement of the present invention is simple and easy toassemble, as the positional relationship between the hydraulic pump andthe electric motor can be easily adapted, e.g. to align the shaft of theelectric motor with the shaft of the hydraulic pump before coupling bothparts together with the connection means. By providing the adjustmentmechanism, costs of the driving arrangement can be decreasedsignificantly, as larger tolerances are acceptable, for example.

According to an embodiment, the connection means is configured as anelastic coupling. The elastic coupling may be an elastic material whichis elastically deformable by loads applied thereto during the intendeduse of the driving arrangement. The elastic coupling may be a mechanicalor a hydraulic coupling. Configuring the connection means as an elasticcoupling results in high operational stability, as disturbances appliedto one of the components are not directly transferred to the other onevia the connection means. Furthermore, if the connection means areconfigured as elastic coupling, the adjustment mechanism of the drivingarrangement of the present invention is particularly advantageous, as itallows for an easy alignment of the shafts of electric motor andhydraulic pump with respect to each other.

The adjustment mechanism may be configured to allow for an adjustment ofthe positional relationship between the electric motor and the hydraulicpump in two different directions. Preferably, said two directions areoriented perpendicular to each other and/or correspond to the verticaland depth direction of the driving arrangement. The vertical directionmay correspond to the vertical direction of the construction machinewhen the driving arrangement is mounted thereto in the intended fashion.Furthermore, a length direction of the driving arrangement may runparallel to the shaft of the electric motor and/or the hydraulic pumpand/or may be perpendicular to the vertical direction. A depth directionmay be defined as being perpendicular to both the length and verticaldirections of the driving arrangement. This embodiment allows for aneffective and precise alignment of the electric motor and the hydraulicpump.

According to an embodiment, the supporting device comprises a baseportion, which may be formed in a plate-like shape. A plate-like shapemay exhibit extensions in two directions, which are perpendicular toeach other, which are significantly larger than the extension of theportion in a third direction, which is perpendicular to the other twodirections. One of the hydraulic pump and the electric motor may beprovided stationary with respect to the base portion and the other oneof the hydraulic pump and the electric motor may be provideddisplaceable with respect to the base portion via the adjustmentmechanism. Preferably, the hydraulic pump is fixedly connected to thebase portion and the electric motor is provided in a displaceablefashion. This embodiment provides a driving arrangement with anadjustment mechanism exhibiting low complexity as only one of thecomponents is provided displaceable.

For providing the displaceability, the supporting device may comprise amounting portion, which is attached to the displaceable one of thehydraulic pump and the electric motor. The mounting portion is connectedto the base portion in a displaceable manner, e.g. via an adjustmentscrew. By applying a torque to the adjustment screw, the positionalrelationship between the mounting portion and the base portion can beadjusted. The mounting portion may be integrally formed from a singlecomponent or from multiple components, which are connected to eachother, e.g. via material bonding, in particular via welding. In thisregard, it is further conceivable that the mounting portion is connectedto the base portion via multiple adjustment screws. This embodimentprovides a driving arrangement with an adjustment mechanism exhibitinglow complexity and being easy to use. Specifically, to adjust apositional relationship between the hydraulic pump and the electricmotor, only an adjustment screw must be turned.

The mounting portion may be connected to the base portion via a verticaladjustment screw for adjusting the vertical position of the electricmotor and the hydraulic pump with respect to each other, and via ahorizontal adjustment screw for adjusting the horizontal positions ofthe hydraulic pump and the electric motor with respect to each other.The horizontal positional relationship may be a positional relationshipof both components in the depth direction of the driving arrangement.This embodiment provides an adjustment mechanism with high flexibilitythat is easy to use. Specifically, by providing the ability to adjust apositional relationship in vertical and horizontal directions, theelectric motor and the hydraulic pump can be optimally aligned withrespect to each other.

According to an embodiment, the supporting device comprises two of theabove described mounting portions, which are provided on opposite sidesof the displaceable one of the hydraulic pump and the electric motor.Both of the mounting portions can be connected to the base portion viaone or multiple vertical and/or horizontal adjustment screws. Themounting portions can be provided in parallel to each other andsubstantially perpendicular to the base portion. This embodiment resultsin a driving arrangement with high stability as the electric motor orthe hydraulic pump is supported on two opposing sides, thereby reducingstresses in the supporting device.

According to an embodiment, the supporting device comprises a pumpmounting portion, which may be formed in a plate-like fashion. The pumpmounting portion may be provided vertically/upright on the base portion.Furthermore, the pump mounting portion may be provided at one of theends of the base portion and/or may comprise a first mounting surfacefacing away from the base portion. To said mounting surface, thehydraulic pump may be attached, e.g. via one or multiple bolts and/orscrews. The electric motor may be provided on the other side of the pumpmounting portion to be positioned above the base portion. Furthermore,the pump mounting portion may exhibit an opening, e.g. a through-hole,in which the connection means may be positioned via which the electricmotor positioned on one side of the pump mounting portion and thehydraulic pump positioned on the other side of the pump mounting portionare connected. This embodiment results in a driving arrangement withhigh mechanical stability as the relatively heavy electric motor isprovided above the base portion. Furthermore, it results in a drivingarrangement that is particularly compact, as the space of the supportingdevice is minimized by arranging the hydraulic pump to extend away fromthe base portion.

According to an embodiment, the driving arrangement further comprises adamping device provided at the supporting device for mounting thedriving arrangement to the construction machine via the damping device.The damping device may be provided between the base portion describedabove and the construction machine to which the driving arrangement ismounted. The damping device may be a mechanical and/or a hydraulicdamping device. E.g. the damping device may comprise one or multiplehydraulic damping cylinders and/or one or multiple rubber pads. Thedamping device results in a high operational safety, as it damps shocksexerted on the driving arrangement through the construction machine,thereby minimizing loads exerted on the hydraulic pump and the electricmotor.

The present invention further relates to a construction machinecomprising a driving arrangement according to one of the above describedembodiments. The construction machine may be an excavator having aconfiguration as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a driving arrangement for a construction machine accordingto an embodiment of the present invention in a first perspective view.

FIG. 2 shows the driving arrangement of FIG. 1 in a further perspectiveview.

FIG. 3 shows a base element of a supporting device of the drivingarrangement of FIGS. 1 and 2.

FIG. 4 shows a partial sectional view for illustrating a connection ofan electric motor to the base element of FIG. 3.

FIGS. 5-6 show the configuration of a vertical adjustment screw of thedriving arrangement of FIGS. 1 and 2.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a driving arrangement 1 for a construction machineaccording to an embodiment of the present invention in differentperspective views. In the present embodiment, the construction machineis an excavator comprising an undercarriage and a superstructure, whichis pivotably with respect to the undercarriage. On the superstructure ofthe excavator, an operator's cabin and a boom with a working equipmentat its distal end are provided. The excavator may be a pure electricexcavator, implying that the locomotion of the excavator, the actuationof the boom and the actuation of the swing drive between theundercarriage and the superstructure are powered by electrical energyonly. The electrical energy for powering those devices may be stored inmultiple battery modules provided on top of the excavator'ssuperstructure, wherein said battery modules may function as theexcavator's counterweight. The excavator may comprise one or multipleelectric motors for powering tracks provided at the excavator'sundercarriage to move the excavator backwards, forwards and sidewards.In addition, the excavator may comprise an additional electric motor forpowering the excavator's swing drive.

The driving arrangement 1, which is shown in FIGS. 1 to 2, may bemounted to the excavator's superstructure. The driving arrangement 1 ofthe present embodiment comprises a hydraulic pump 2 for poweringmultiple hydraulic cylinders of the excavator's boom via a hydrauliccircuit. Specifically, the excavator comprises a boom with multiplearms, which are movable with respect to each other via hydrauliccylinders. The hydraulic cylinders are part of a hydraulic circuit,which is powered by the hydraulic pump 2 of the driving arrangement 1 ofthe present embodiment. Furthermore, the driving arrangement 1 comprisesan electric motor 3, which is powered by electric energy of theexcavator's battery modules. The electric motor 3 comprises a lateralsurface 4, a front surface 5 and a back surface 6, wherein the motor'sshaft is oriented symmetrically with respect to the lateral surface 4and is accessible via the front surface 5. In addition, the drivingarrangement 1 comprises a connection means 7, which is configured as anelastic coupling in the present embodiment. The connection means 7 isprovided between the electric motor 3 and the hydraulic pump 2 fortransferring power of the electric motor 3 to the hydraulic pump 2.

Furthermore, the driving arrangement 1 comprises a supporting device 8for mounting the driving arrangement 1 to the construction machine. Thesupporting device 8 is configured to support the electric motor 3 andthe hydraulic pump 2 as well as the connection means 7. The supportingdevice 8 comprises a base element 9, which is illustrated in FIG. 3. Thebase element 9 exhibits a substantially rectangular plate-like baseportion 10 via which the driving arrangement 1 can be mounted to theconstruction machine. Specifically, the base portion 10 comprises adamping device with four damping units 11.1, 11.2, 11.3, 11.4, which areshown in FIGS. 1 and 2, via which the driving arrangement 1 can bemounted to the construction machine. In the present embodiment, thedamping units 11.1, 11.2, 11.3, 11.4 are configured as mechanicaldamping units, e.g. rubber plates, which are placed between the baseportion 10 of the base element 9 and the construction machine, whereinthe damping units are provided at the corners of the plate-like baseportion 10. The base portion 10 is oriented horizontally when thedriving arrangement 1 is attached to the construction machine in theintended fashion.

In addition, the base element 9 comprises a vertical plate-like pumpmounting portion 12, which is provided upright on and in parallel to theshort narrow side surfaces of the rectangular plate-like base portion10. The pump mounting portion 12 is formed symmetrically and exhibits athrough-hole 13, which is provided substantially centrally. Furthermore,as derivable from FIG. 3, the pump mounting portion 12 is situatedoffset and in proximity to one of the short narrow side surfaces of thebase portion 10. Further, the base element 9 comprises a firststrengthening portion 14.1 and a second strengthening portion 14.2,which respectively extend in parallel to the long narrow side surfacesof the base portion 10, are formed plate-like, and are provided uprightin a vertical fashion on the base portion 10. The strengthening portions14.1 and 14.2 extend approximately along the entire length of the baseportion 10 and engage with the pump mounting portion 12. In the area, inwhich the supporting portions 14.1, 14.2 engage with the pump mountingportion 12, they respectively exhibit a protruding portion forincreasing the surface contact between both parts. The pump mountingportion 12 and the strengthening portions 14.1, 14.2 are welded to eachother, wherein all three parts are also respectively welded to the baseportion 10. The strengthening portions 14.1, 14.2 serve as strengtheningmeans for strengthening the connection between the pump mounting portion12 and the base portion 10, thereby fixing the positional relationshipbetween both parts. The entire base element 9 is made from steel.

As derivable from FIGS. 1 and 2, the hydraulic pump 2 is connected to amounting surface 16 of the pump mounting portion 12, which is facingaway from the base portion 10. In the present embodiment, the hydraulicpump 2 is attached to the pump mounting portion 12 with multiple boltsand/or screws, as shown in FIG. 2, for fixing the positionalrelationship between the base element 9 and the hydraulic pump 2. Theconnection means 7, which is coupled with the shaft of the hydraulicpump 2, is fixed in the through-hole 13 of the pump mounting portion 12.The electric motor 3 is positioned above the base portion 10 and betweenthe strengthening sections 14.1, 14.2 of the base element 9. Asderivable from FIG. 3, the base portion 10 exhibits a cut-out 15 betweenthe damping units 11.3, 11.4 provided on the mounting surface 16 side ofthe mounting portion 12 for allowing good accessibility to the hydraulicpump 2. Further, as derivable from FIG. 3, the base portion 10 exhibitsa central cut-out 30 for accommodating the bottom portion of theelectric motor 3, thereby allowing for a compact design of the drivingarrangement 1.

In addition, the driving arrangement 1 comprises an adjustment mechanismfor adjusting the positional relationship between the electric motor 3and the base portion 10 of the base element 9. Specifically, theadjustment mechanism of the present embodiment is configured to adjustthe positional relationship between those two parts in verticaldirection V and in depth direction T of the driving arrangement 1. Asthe connection means 7 and the hydraulic pump 2 are provided stationarywith respect to the base portion 10 of the base element 9, theadjustment mechanism allows for an adjustment of the positionalrelationship between the electric motor 3 and the hydraulic pump 2 invertical direction V and in depth direction T.

In the present embodiment, the adjustment mechanism is embodied by thesupporting device 8. For that purpose, the supporting device 8 comprisestwo plate-like mounting portions 17.1, 17.2, which are provided uprightand in vertical fashion on the base portion 10. The mounting portion17.1, 17.2 are attached to the right and left sides of the lateralsurface 4 of the electric motor 3 via multiple bolts and/or screws, asshown in FIG. 4. Furthermore, as derivable from FIG. 4, the mountingportion 17.1, 17.2 are oriented in parallel to the strengtheningportions 14.1, 14.2 of the base element 9. In depth direction T of thedriving arrangement 1, the mounting portions 17.1, 17.2 are respectivelyprovided outside of the strengthening portions 14.1, 14.2, as shown inFIG. 4. At their bottom end, the mounting portions 17.1, 17.2respectively exhibit a plate-like lip portion 18.1, 18.2, which isoriented perpendicular to the remaining mounting portions 17.1, 17.2such that the entire mounting portions 17.1, 17.2 exhibit asubstantially L-shaped cross section.

The lip portions 18.1, 18.2 are provided horizontally and parallel tothe base portion 10 of the base element 9.

The mounting portions 17.1, 17.2 are connected to the base portion 10via vertical adjustment screws 19. Specifically, each lip portion 18.1,18.2 is connected to the base portion 8 via two vertical adjustmentscrews 19. As derivable from FIGS. 5 and 6, the vertical adjustmentscrews 19 exhibit a hexagonal head 20 for turning of the screw and acylindrical portion 21 with an outer thread. At the end opposite to thehexagonal head 20, the vertical adjustment screws 19 exhibit a planarengagement surface 22. The planar engagement surface 22 of the verticaladjustment screws 19 engages with the top surface of the base portion 10to form a planar contact. Furthermore, the outer thread of thecylindrical portion 21 of the vertical adjustment screws 19 engages withan inner thread formed in the respective lip portion 18.1, 18.2 of themounting portions 17.1, 17.2. By applying a torque to the hexagonal head20 of the vertical adjustment screw 19, the outer thread 21 is turnedrelatively to the inner thread of the lip portion 18.1, 18.2, therebymoving the lip portion 18.1, 18.2 in vertical direction V with respectto the base portion 10, as the front surface 22 of the verticaladjustment screw 19 is in planar engagement with the base portion 10. Asthe electric motor 3 is mounted to the lip portions 18.1, 18.2 via themounting portions 17.1, 17.2, turning of the vertical adjustments screws19 displaces the electric motor 3 with respect to the base portion 10and therefore with respect to the hydraulic pump 2 in vertical directionV.

Furthermore, as derivable from FIG. 4, the mounting portions 17.1, 17.2are respectively connected to the strengthening portions 14.1, 14.2 ofthe base element 9 with two horizontal adjustment screws 25. Byloosening the horizontal adjustment screws 25 of one of the mountingportions 17.1 and tightening the adjustment screws 25 of the other oneof the mounting portions 17.2, the mounting portions 17.1, 17.2 andtherefore the electric motor 3 may moved with respect to the baseportion 10 and thus with respect to the hydraulic pump 2 in depthdirection T.

1. A driving arrangement for a construction machine, comprising: ahydraulic pump for powering a working equipment and/or locomotion of theconstruction machine through a hydraulic circuit; an electric motor fordriving the hydraulic pump, wherein power of the electric motor istransferable to the hydraulic pump via a connection means; a supportingdevice for mounting the driving arrangement to the construction machine,the supporting device supporting the hydraulic pump and the electricmotor; and an adjustment mechanism for adjusting the positionalrelationship between the electric motor and the hydraulic pump to alignthe electric motor and the hydraulic pump with respect to each other. 2.The driving arrangement according to claim 1, wherein the connectionmeans is configured as an elastic coupling.
 3. The driving arrangementaccording to claim 1, wherein the adjustment mechanism allows for anadjustment of the positional relationship in two different directions,and wherein the two different directions are orthogonal to each otherand/or correspond to the vertical and depth directions of the drivingarrangement.
 4. The driving arrangement according to claim 1, whereinthe supporting device comprises a base portion for mounting the drivingarrangement to the construction machine, and wherein one of thehydraulic pump and the electric motor is displaceable with respect tothe base portion via the adjustment mechanism and the other isstationary with respect to the base portion.
 5. The driving arrangementaccording to claim 4, wherein the supporting device comprises a mountingportion to which the displaceable one of the hydraulic pump and theelectric motor is mounted, the mounting portion being connected to thebase portion via an adjustment screw for adjusting the positionalrelationship between the mounting portion and the base portion.
 6. Thedriving arrangement according to claim 3, wherein the mounting portionis connected to the base portion via a vertical adjustment screw foradjusting the vertical positions and a horizontal adjustment screw foradjusting the horizontal positions of the hydraulic pump and theelectric motor with respect to each other.
 7. The driving arrangementaccording to claim 5, wherein the supporting device comprises two of themounting portions, and wherein the two mounting portions are provided onopposite sides of the displaceable one of the hydraulic pump and theelectric motor.
 8. The driving arrangement according to claim 4, whereinthe supporting device comprises a pump mounting portion at one of theends of the base portion, wherein the electric motor is displaceableabove the base portion, and wherein the hydraulic pump is mounted to thepump mounting portion to extend away from the base portion.
 9. Thedriving arrangement according to claim 1, further comprising a dampingdevice provided at the supporting device for mounting the drivingarrangement to the construction machine via the damping device.
 10. Aconstruction machine, comprising a driving arrangement according toclaim
 1. 11. The driving arrangement according to claim 1, wherein theconstruction machine is an excavator.
 12. The construction machineaccording to claim 10, wherein the construction machine is an excavator.